Blood culture collection – OSCE guide

Taking blood cultures is a relatively common OSCE station. You’ll be expected to demonstrate your clinical skills and ability to communicate effectively. This blood culture collection OSCE guide provides a clear, concise, step by step approach to obtaining blood cultures. There is wide variation in the type of equipment used for obtaining blood cultures and therefore you should always follow your medical school or local hospital’s guidance. You should note however that blood cultures should ALWAYS be obtained via a fresh stab and not use existing peripheral lines. If a patient has a central line blood may be taken from this if investigating a source of infection where the line is a potential source, however, this should be done in combination with a peripheral sample (which should be taken first). Check out the blood culture collection OSCE mark scheme here.

Use 2% chlorhexidine in 70% isopropyl alcohol to disinfect the patient’s skin and allow to dry

If the patient’s skin is visibly soiled use soap and water to clean the site

Once the skin has been disinfected you should not touch the site again (even with gloves on)

8. Wash your hands:

Using alcohol gel and the World Health Organisation’s hand hygiene technique show in our guide here

If your skin is visibly soiled you should wash your hands using soap and water

9. Don apron and gloves

10.Remove caps from the blood culture bottles immediately prior to taking the sample and clean the top of each with a separate cleaning swab, allowing the alcohol to evaporate for 30 seconds before proceeding with bottle inoculation.

Insertion of the needle

1.Unsheathe the needle

2.Anchor the vein from below with your non-dominant hand by gently pulling on the skin distal to the insertion site

3.Warn the patient of a sharp scratch

4.Insert the needle through the skin at a 30-degree angle or less, with the bevel facing upwards (you should feel a decrease in resistance as the needle enters the vein)

5.Advance the needle a further 1-2 mm into the vein after the decrease in resistance is felt

6.Lower and anchor the needle to the patient’s skin

7.Use the other hand to attach the aerobic blood culture bottle to the adapter, piercing the blood culture septum and allowing the bottle to fill with 10ml of blood (using the bottle’s graduation lines to accurately gauge sample volume)

8.Remove the aerobic bottle and then attach the anaerobic bottle, also filling it with 10ml of blood

9.Release the tourniquet

10.Withdraw the needle and then apply gentle pressure to the site with some sterile gauze

11.Ask the patient to hold the gauze in place whilst you dispose of the needle into a sharps container

References

1. Taking blood cultures. A summary of best practices. UK Government Web Archive. Published 2011[LINK]

2. WHO guidelines on drawing blood: best practices in phlebotomy. Published 2010. [LINK]

3. WHO Guidelines on Hand Hygiene in Healthcare: a Summary. Published 2009. [LINK]

Assessment

Washes handsIntroduces themselvesConfirms patient's detailsExplains procedure and gains consentChecks for allergiesGathers equipmentPrepares blood collection set using ANTTPlaces sharps bin and equipment tray within easy reachPositions patient’s arm appropriately and inspects for a suitable veinApplies tourniquet and palpates the veinCleans site with 2% chlorhexidine in 70% isopropyl alcohol & and allows it to dryWashes handsDons apron and glovesRemoves caps from blood culture bottles and cleans the top of each with a separate cleaning
swabUnsheathes needleAnchors vein and warns patient of a sharp scratchInserts needle at a 30-degree angle or less with the bevel facing upwardsAnchors needle to patient’s skinFills aerobic then anaerobic bottles with at least 10mls of blood eachReleases the tourniquetWithdraws the needleApplies pressure to puncture site with cotton wool or gauzeDiscards needle into sharps containerDresses puncture site and disposes of clinical waste appropriatelyWashes hands and thanks patientLabels samples at the bedside and documents reason for blood culture